Cable-gripper



-une 7, 1938. E. F. DWIGHT 2,120,066

CABLE GRIPPER Filed March 24, 19.37

42g s4 @76.5 l sa i Patented June 7, 1938 Y UNITED STATES PATENT OFFICE CABLE-GRIPPER Edmund F. Dwight, Portsmouth, N. H.

Application March 24, 1937, Serial No. 132,873

11 Claims. (Cl. 104-218) This invention relates to cable-cars and is the grips without quite setting them tov clamp the concerned with gripper mechanism by which a cable. This latter function is utilized to confine car may be operatively connected to and released the cable loosely in the grips so that it will surefrom a cable. The invention is herein illustrated 1y be under control when the time comes to send fr as designed to expedite the dispatch of cable-cars the car on its way. v 5 of the type commonly employed to convey coal Another novel feature consists in an improved from a station near a vessel to points f discombination including a locking or latching charge in a coal-yard. member for maintaining one or more predeter- In one type of conveyor system for the purpose mined relations of the grips. As herein illusi0' above mentioned, the cars are towed individually trated, this latching member is carried by the 10 around a circuit by an endless cable that prooperating member and is arranged to perform vides an inbound stretch and an outbound its latching duty by co-acting with a cam-folstretch both arranged to run past the loading lower against Vwhich the aforesaid operating surstation. 'Ihe portion connecting these stretches face acts. To utilize the latching member for lL forms a loop and runs over one or more driving two purposes it is provided with two shoulders I5 drums or sheaves. in series, one to prevent relative releasing move- In such a system two attendants have herement of the grips when they are set to conne tofore been required to perform the necessary the cable loosely, and the other to prevent such routine at a loading station in the short interval releasing movement when they are set to `clamp n of time allotted to each car. This is because a the cable. large share of the time has been required to open Still another novel feature of the invention the grips, transfer them from the inbound consists in an organization in which the weight stretch to the outbound stretch of the cable, set of one of the grips, when applied to the aforethem up far enough to conne the outbound said quick-acting portion of the operating surstretch without clamping it, and nally to set face, will furnish all the force necessary to open `2'5 them up tightly to apply the necessary clamping the grips and shift the operating member to a pressure. In addition to these items of duty the corresponding position at one limit of its range routine required at the loading station includes of operating movement.

applying the brakes and opening and closing a Referring to the drawing, gate to discharge a load of four tons, more or Fig. l is a top-plan view of the rear end of a 30 less, from a chute into a standing car. car provided with cable-gripping mechanism With a view to eXpediting the routine at a loadembodying the present invention; ing station, and thereby releasing one of the at- Fig. 2 is a rear elevation of a car so equipped; tendants for duty elsewhere, the present inven- Fig. 3 is a rear elevation of the cable-gripping tion provides an improved outboard gripper mechanism on a larger scale. 35 mechanism capable of being operated much more Fig. 4 is a horizontal section indicated by line rapidly and with more certainty of' control than IV-IV in Fig. 3; the gripper mechanisms heretofore provided for Fig. 5 is a horizontal section in the plane indisimilar use. In consequence of the improvements cated by line V-V in Fig. 3; 4U' hereinafter described and claimed, one attendant Fig. 6 is a vertical section of the platform 40 may readily perform all the aforesaid duties at a structure that provides a mounting for the griploading station without requiring any more time per mechanism, the plane of the section being inthan two attendants have required when operatdicated by line VI-VI in Fig. 2 but some of the ing with gripper mechanisms of former conparts of the gripper mechaniSm being Omtted; struction. Fig. 7 is a vertical section of a sleeve that acts 45 One novel feature of the invention consists in as a part of the female grip when the parts are an improved gripper mechanism comprising an assembled in their co-operative relation;

operating member having an operating surface Fig. 8 is a perspective View of a locking orY rethat includes a steep quick-acting camming portaining member intended to surround the upper lo tion, a shoulder and a land tangent to the shoulportion of the sleeve shown in Fig. 7; 50 der. The land is arranged to maintain a certain Fig. 9 is a perspective view of an operating predetermined clamping relation of the grips, the member intended to surround the lower portion shoulder is arranged to establish that relation, of the sleeve shown in Fig. 7; and and the quick-acting camming portion is ar- Fig. 19 is an elevation of the parts otherwise rangedl to effect the major relative movement of represented in the upper portion of Fig. 3, the 55' l and 2 may be regarded as the inbound stretch one pair appears in Fig. 2, run on rails I2.

member in Fig. lOoccupies an intermediate position in its range of operating movement.

n The car, incompletely Vrepresented in Figs. 1 and 2, is of a type commonly employed in coalyards to which coal is transported in vessels. To avoid obscuring the mechanism with which the present invention is concerned, certain non-relatedparts of the car are omitted, and only the lowerportion of the coal compartment or body I9 of the car isrepresented. The wheels II, of which An endless cable for to-wing cars runs Abetween the rails I2. According to common usage the track, comprising the rails I2, is laid out to provide an endless circuit in which a series of cars are conveyed individually to carry coal from aloading station adjacent to a vessel to various points along the circuit where they discharge their loads. Moreover, the power-plant (not shown) for driving the cable is commonly situated adjacent to the loading station, and a loop is formed in the cable which runs from the outbound side ofk that station to and around the driving sheaves of the power-plant and thence back to the track at the inbound side of the station. This loop provides equipped may be transferred from the` inbound Vstretch of the cable to the outbound stretch while the car is coasting to its loading position at the loading station. The stretch I4 of the cable represented in Figs.

at the loading` station, and the stretch I5 may be regarded as the outbound stretch. The gripper mechanism hereinafter described is mounted on a horizontal platform I6 attached to the rear end of a car. As each car approaches the loading station an attendant operates the gripper mechanism to release it from the inbound stretch I4 of the cable, shifts the gripsfrom the inbound stretch to the outbound stretch, operates the gripper mechanism to an extent sufficient only to conne the outbound stretch loosely in the grips, operates. the brake mechanism (not shown) with which each car is equipped, loads the car, and finally operates the gripper mechanism to set the grips tightly on the cable.

To enable one attendant to perform all the duties that have hitherto required two attendants at a loading station, the gripper mechanisms must be capable of being operated much vvmore rapidly than any heretofore provided, and

at the same time the individual stages of their operation must be definitely controlled so that Y ing lengthwise of the car and projecting to-the rear from the rear wall I8 of the load compartment.Y A larg-e hole I9 in this platform I6 permits the gripper mechanism to extend therethrough with ample clearance for all the movements'of which it must be capable. This hole I9 is covered by a circular disk or turntableV 29 of thick sheet steel, the margin of which overessential difference being that the operatingv laps the rim of the hole I9 and is supported thereby. The turntable is maintained in its operative position by a series of flanged guide-rolls 2l attached to the platform I6 by pivot pins 22 (Fig. 6). The flanges of the rolls 2l overlap the rim of the disk 2) to prevent the latter from being dislodged from the platform.` V The central portion of the disk 20 is cut out to form a hole 23 through which the gripper mechanism may hang. At opposite sides of this hole horizontal bearing blocks 24 are aflixed to the upper surface of the disk 26 to receive Vcylindrical trunnions 25 that pro-ject in opposite Y directions from the male grip 26 of the gripper mechanism. Thus, to enable the grips to follow vthe cable around curves, the described mounting provides not only for angularY movement of the gripper assemblage about the horizontal axis the disk 29 about a vertical axis intersecting the center of the disk.

Referring nowrto the construction of the grip- Y per mechanism and particularly to Figs. 3 and 6, the male grip 25 is provided at its upper Vendwith a flat horizontal seat 21 and at its lower end with a slightly concave gripping surface 28 for engagement with the cable. The female grip comprises a lower member 3U, a cylindrical stern 3|, a cylindrical sleeve 32 (Fig. '7) and nuts 33 and Sil screwed on the upper end of the stem 3l The nut V33 rests on the upper end of the sleeve 32 and provides for relative adjustment of the grips to regulate the pressure with which they may clamp the cable. The lower end 35 of the member 30 has the shape of a hook and is provided with a con Ymovable up and down to grip Vand release the cable. In Fig. 3 the female grip is represented in solid lines as in its position of full release, that is, at the lower limit of its range of verticalV movement.y When in this position the entrance or gap between the grips exceeds the diameter of the cable which may, therefore, be inserted and removed laterally. represent a semi-closed position of the female grip in which the gap is less than the diameter of the cable. This semi-closed position is established at one stage to confine the outbound stretch of the cable loosely so that it may not escape accidentally but still run freely between the gripping surfaces 28 and 36 while the car is coasting and standing still.

As shown in Fig. 5 grooved guides or cheeks 31 formed on the member 30 loosely embrace opposite margins of the member 26 to maintain the grips in coi-operative relation with freedom for relative gripping and releasing movement.

For assembling purposes, the stem 3l is inserted into a bore in the member 30 and is secured to the latter by a pin 38, but before this connection is made the stem is preferably in- Dotted lines in this gure.

serted through a ball-thrust-'bearilng 39 and then through a bore in thehead of the male grip 26 between the trunnions 25. 39 will then be seated on the surface 21 (Fig. 6)

70 The thrust-bearingY of the male grip to support the female grip and to sustain the gripping pressure when the female grip is set up against theV cable. Above the thrust-bearing 39 the stem 3l is provided with a cylindrical portion 40 of relatively large diameter adapted to occupy the chamber 4l in the sleeve 32 (Fig. 7) with freedom for relative adjustment. through the sleeve 32, the lower end of the sleeve is inserted through a locking or latching collar 43 (Fig. 8), this collar then having a bearing. on the sleeve and being loosely confined between the pin 42 and a retaining ange 44 at the upper end of the sleeve. This flange and the cross-pin are spaced apart to permit limited relative upand-down movement of the collar 43 for a purpose hereinafter described.

The lower portion of the sleeve 32 provides a cylindrical bearing for an operating member comprising a barrel portion 45 and an operating handleor lever 46 projecting spoke-wise therefrom. The lower end of the barrel portion is seated on the thrust-bearing 39, if one is provided, but, if desired, the thrust bearing may be omitted, in which case the barrel portion of the operating member may be extended to engage the seat 21 of the male grip 26. When the operating member 45, the sleeve 32 and the locking collar 43 have been assembled on the stem 3l, the cross-pin 42 will be inserted not only through the sleeve but also through a slot 41 in the portion 46 of the stem. The slot 41 is elongated vertically to provide for adjusting the female grip to regulate its maximum gripping pressure. When the parts are thusv assembled, rolls 50 are placed on the projecting ends of the cross-pin 42 to provide diametrically opposite cam-followers. The cross-pin is bored to receive cotterpins, as shown in Figs. 3 and 10, whereby the rolls are maintained in co-operative relation to duplicate operating surfaces formed on the upper end of the barrel portion 45.

Although the functions of the operating member 45 require only one operating surface, the duplex construction about to be described is preferred for the reason that it divides and balances the load between the two operating surfaces and enables the stem 3l to slide up and down in the bore of the male grip 26 without appreciable friction. As shown in Figs. 3, 9 and l0, the duplicate operating surfaces comprise steep, quickacting camming portions 52, horizontal lands 53 and shoulders 54 tangent to both. Abrupt stops 55 project upwardly from the low ends of the camming portions 52, and abrupt stops 56 project upwardly from the remote ends of the'lands 53. These stops co-operate with the cam-followers to limit the extent of turning movement of the operating member 45 to an angle of about 90.

When the operating member is moved clockwise as viewed in Fig. l, from the position shown in Fig. 3 to that shown in Fig. 10, the steep camming portions 52 raise the female grip from the full-open position to the semi-closed position represented in dotted lines at the lower end of Fig. 3, this movement of the female grip being insuicient to apply clamping pressure to the cable and involving no load except the weight of the female grip. Further turning movement of the operating member in the same direction will carry the shoulders 54 under the cam-followers to effect actual clamping o-f the cable, but at this stage the curvature of the cam-followers and their individual rotation on the cross-pin 42 will counteract the supplemental load incidental to compressing and clamping the cable, so that no great effort on the part of the operator will be required. Once the lands 53 are brought into Before the cross-pin 42 is inserted load-sustaining positions little effort isrequired for the iinal stage of movement.

The latching or locking collar 43 also embodies duplicate features of construction by which it is enabled to co-operate with the cam-followers,

first to maintain the operating member in the Y intermediate position shown in Fig. 10, and thereafter in the vilnal position in which both the lands 53 and the arresting shoulders 56 will be in engagement with the'followers. The locking collar is so connected to the operating member 45 as to turn back and forth therewith, but is also free to slide up and down on the sleeve 32, to the end that the force of gravity will operate automatically to render it effective for both purposes above mentioned. A forked lever 60 (Figs. 3 and 4) -straddles the collar 43 and is provided with trunnions 6i that project into alined bearing sockets 62 (Fig. 8) bored in the collar at diametrically opposite points. This lever is carried by and located between a pair of ears formed on the handle 46 (Figs. 1 and 2) and is connected thereto by a fulcrum pin 63. If desired, the collar 43 may be guided by parallel pins anixed to and projecting upwardly from the barrel 45. The collar is provided with bores to slideon these pins. The outer end of the lever 60 serves as a handle and is so related to the main operating handle 46 that both may be grasped in one hand to lift the locking collar 43 and toopen the grips.

As shown in Fig. 8 the collar 43 is provided with duplicate series of stops or abutments 65 and 66 in stepped relation, and with connecting lands 61. rI'he stops 65 are preferably undercut or back-pitched as shown. The collar normally rests by the force of gravity on the cam-followers 50. When the'parts occupy the positions shown in Figs. 2 and 3 the collar is of no effect, but when the operating member is turned to the intermediate position shown in Fig. 10, the undercut abutments 65 drop behind the followers to maintain the female grip in the semi-closed position represented by dotted lines at the lower end of Fig. 3, so that a cable may run freely between the grips and yet not escape from their embrace. Although, at this stage, the load on the steep portions 52 of the operating surfaces applies a considerable torque to the colla-r 43, the guide-pins 51 and the trunnions 6I (Fig. 4) are relieved of the torsional stress by the abutments 55 of the operating member and the counterparts of the collar 43 that lie against them. Moreover, since the abutments 65 are undercut, their pressure against the cam-followers applies a component of downward force to the collar 43 supplemental to the force of gravity. Consequently, the tendency of the operating member to let the female grip down actually secures the collar more rmly in its latching position to guard against accidental release of the operating member.Y

Fig. 1 represents the operating handle 46 in its three positions of dwell, indicated respectively at A, B and C, position C corresponding to that shown in Fig. 3, position B corresponding to that represented in Fig. 10, and position AV being the gripping position at which the handle stands when the car is being towed by the cable. As each car approaches the loading station, the attendant will advance to meet it, step behind it, shift the handle from position A to position C to release the cable, and bear down on the operating handle to swing the gripper mechanism on its trunnions 25 far enough to carry the female grip over and beyond the outbound cable I5. I-le will then place the outbound cable Yin the hooked. end of the female grip and swing the operating handle from position C to position B,

thereby raising the female grip to its semi-closed position indicated by dotted Ylines at the lower 'Y ing chute to discharge a load of four tons, more` or less, linto the standing car. Having loaded the car and closed the loading gate, the attendant still has sufficient time in which toY complete the closing movement of the female grip by shifting the operating handle 46 from position B to position Al before the next succeeding car is within striking distance. operator will preferably exert at first only enough effort to effect a gradual starting of the car since it is not desirable to load the cable too suddenly. Accordingly, after the gripping pressure has been set up sufficiently tov start the vcar slowly, the attendant has merely to apply a final thrust to completethe movement of the operating handle to position A, and since the car will now be traveling its forward progress will furnish components of force and movement counter to the final effort of the attendant. These opposing factors of force and movement will expedite the finalV stage of operation whereby the handle l5 is shifted to its trailing position indicated at A.

Having thus described the invention, what I claim as new and Vdesire to secure by Letters Patent of the United States is: f Y

1. A cable-gripper comprising a male grip and a female grip having connecting portions by which they are co-operatively related, one of said grips having a cam-follower andthe other having a seat facing the latter and an operating member arranged to act on said seatand said .cam-follower for relatively moving them to clamp, unclamp and release aV cable, said operating member having an operatingsurface comprising a steep quick-acting camming portion, a shoulder and a land tangent to the latter, said land being arranged to maintain a certain predetermined clamping relation of the grips, said shoulder being arranged to establish said relation, and said steep portion having a range sufcient to provide for lateral insertion of a cable between the grips.

2. A cable-gripper as defined in claim 1 in which the operating member is sustained in its operative relation to one of said grips by the other grip.

3. A cable-gripper as defined in claim 1 in which the operating member comprises a cylindrical barrel arranged to be Vturned about its axis and provided with duplicate operating surfaces the corresponding points of which are diametrically opposite one another, said -duplicate surfaces being arranged to effect relative clamping movement of the-grips.

4. A cable-gripperV comprising a male grip and a female grip having one a stem and the other a bearing in which said stem is arranged to slide, a cross-pin intersecting said stem and projecting radially therefrom at points spaced from said bearing, cam-rolls arranged on the projecting portions of Vsaid cross-pin, and an oper- At this stage the K Y ing said stem between said bearing and said cam-V rolls, one end of said barrel portion engaging said bearing, and the other end having duplicate operating surfaces arranged to operate against said cam-rolls to effect relative clamping movement of said grips in consequence of turning movement of said barrel portion about the axis of said stem.' Y

` 5. A cable-gripper as defined in claim 4 and comprising also a sleeve surrounding said stemy and engaging said cross-pin totransmit the operating movement thereof to the stem, and means for relatively adjusting said sleeve and said stem to regulate the maximum clamping pressure applicable to the grips by said operating member.

6. A cable-gripper as defined in claim 4 and comprising also a sleeve surrounding sai-d stem and extending into said barrel portionto provide a bearing for the latter, said cross-pin intersecting, and having bearings in, said sleeve to transmit operating movement thereto, and an Vabut- Y ment on said stem against which said sleeve abuts which one of the grips is provided with a project-V ing cam-follower to cooperate with said operating surface, and in which a latching member is carried by said operating member to cooperate with said follower to prevent relative openin movement of the grips.

9. A cable-gripper as defined in claim l, in which a latching member is carried bysaid. operating member and provided with a seriesV of shoulders arranged to cooperate successively with said follower to prevent relative opening movement of the grips.

10. A cable-gripper as defined in claim 1, in which the operating member kconsists of a barrel portion and an operating handle projecting spoke-wise therefrom, said operating surface being at one end of said barrel portion and the opposite end thereof being sustained by an antifriction thrust-bearing on said seat.

11. In a cable-car of the type in which an outboard gripper mechanism is arranged to be operated by an attendant standing on or beside the track, an operating member for said mechanism arranged to be turned about an axis through a limited range of virtuallyV ninety degrees, said member having a barrel portion and an operating handle projecting spoke-wise therefrom, and cooperative grips'by which said operating member is carried, said grips having onea cam-follower and the other a seat for one end of said barrel portion, and the other' end of said barrel portion having an operating surface comprising a steep quick-acting camming portion by which EDMUND F. DWIGHT. 

